Electro-optical device and method for manufacturing the same

Abstract

An electro-optical device and a method for manufacturing the same are disclosed. The device comprises a pair of substrates and an electro-optical modulating layer (e.g. a liquid crystal layer having sandwiched therebetween, said pair of substrates consisting of a first substrate having provided thereon a plurality of gate wires, a plurality of source (drain) wires, and a pixel matrix comprising thin film transistors, and a second substrate facing the first substrate, wherein, among the peripheral circuits having established on the first substrate and being connected to the matrix wirings for the X direction and the Y direction, only a part of said peripheral circuits is constructed from thin film semiconductor devices fabricated by the same process utilized for an active device, and the rest of the peripheral circuits is constructed from semiconductor chips. The liquid crystal display device according to the present invention is characterized by that the peripheral circuits are not wholly fabricated into thin film transistors, but only those portions having a simple device structure, or those composed of a small number of devices, or those comprising an IC not easily available commercially, or those comprising an expensive integrated circuit, are fabricated by thin film transistors. According to the present invention, an electro-optical device is provided at an increased production yield with a reduced production cost.

What is claimed is:  
     
       1. A display device comprising;
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one first thin film transistor wherein a gate electrode of said first thin film transistor is electrically connected to one of said plurality of first signal lines and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 a smoothing film comprising an organic resin formed over said switching elements;  
 a plurality of pixel electrodes formed over said smoothing film and electrically connected to said switching elements through contact holes formed in said smoothing film; and  
 a first driver circuit comprising at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines, wherein said second driver circuit comprises second thin film transistors formed over said substrate.  
 
     
     
       2. The display device according to  claim 1  wherein said pixel electrodes comprise indium tin oxide. 
     
     
       3. The display device according to  claim 1  wherein at least one of said first and second thin film transistors has a channel region comprising semi-amorphous silicon. 
     
     
       4. The display device according to  claim 1  wherein each of said first and second thin film transistors has a top-gate structure. 
     
     
       5. The display device according to  claim 1  wherein said smoothing film comprises polyimide. 
     
     
       6. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one first thin film transistor, wherein a gate electrode ol said first thin film transistor is electrically connected to one of said plurality of first signal hues and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 a smoothing film comrising an organic resin fonned over said switching elements;  
 a plurality of pixel electrodes formed over said smoothing film and electrically connected to said switching elements through contact holes formed in said smoothing film; and  
 a first driver circuit comprising at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines, wherein said second driver circuit comprises second thin film transistors formed over said substrate,  
 wherein said first driver circuit is connected to said substrate through a tape automated bonding process.  
 
     
     
       7. The display device according to  claim 6  wherein said IC chip is mounted on a flexible support. 
     
     
       8. The display device according to  claim 6  wherein said pixel electrodes comprise indium tin oxide. 
     
     
       9. The display device according to  claim 6  wherein at least one of said first and second thin film transistors has a channel region comprising semi-amorphous silicon. 
     
     
       10. The display device according to  claim 6  wherein each of said first and second thin film transistors has a top-gate structure. 
     
     
       11. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one thin film transistor;  
 a smoothing film comprising an organic resin formed over said switching elements;  
 a plurality of pixel electrodes formed over said smoothing film and electrically connected to said switching elements through contact holes formed in said smoothing film; and  
 a driver circuit comprising at least one IC chip for driving said switching elements,  
 wherein said IC chip is formed on a flexible support and said flexible support is connected to said substrate.  
 
     
     
       12. The display device according to  claim 11  wherein said thin film transistor has a top-gate structure. 
     
     
       13. The display device according to  claim 11  wherein said pixel electrodes comprise indium tin oxide. 
     
     
       14. The display device according to  claim 11  wherein said IC chip is electrically connected to either one of said first signal lines or said second signal lines. 
     
     
       15. The display device according to  claim 11  wherein said driver circuit further comprises thin film transistors formed over said substrate. 
     
     
       16. The display device according to  claim 11  wherein said thin film transistor has a channel region comprising semi-amorphous silicon. 
     
     
       17. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one first thin film transistor, wherein a gate electrode of said first thin film transistor is electrically connected to one of said plurality of first signal lines and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 a smoothing film comprising an organic resin formed over said switching elements;  
 a plurality of pixel electrodes formed over said smoothing film and electrically connected to said switching elements through contact holes formed in said smoothing film; and  
 a first driver circuit comprising at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines wherein said second driver circuit comprises second thin film transistors formed over said substrate,  
 wherein said IC chip is mounted over said substrate.  
 
     
     
       18. The display device according to  claim 17  wherein each of said first and second thin film transistors has a top-gate structure. 
     
     
       19. The display device according to  claim 17  wherein said pixel electrode comprise indium tin oxide. 
     
     
       20. The display device according to  claim 17  wherein at least one of said first and second thin film transistors has a channel region comprising semi-amorphous silicon. 
     
     
       21. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switchihg elements comprising at least one first thin film transistor wherein a gate electrode of said first thin film transistor is electrically connected to one of said plurality of first signal lines and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 an organic resin film formed over said switching elements;  
 a plurality of pixel electrodes formed over said organic resin film and electrically connected to said switching elements through contact holes formed in said organic resin film; and  
 a first driver circuit comprising at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines, wherein said second driver circuit comprises second thin film transistors formed over said substrate.  
 
     
     
       22. The display device according to  claim 21  wherein said organic resin film comprises polyimide. 
     
     
       23. The display device according to  claim 21  wherein each of said first and second thin film transistors has a top-gate structure. 
     
     
       24. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one thin film transistor;  
 an organic resin film formed over said switching elements;  
 a plurality of pixel electrodes formed over said organic resin film and electrically connected to said switching elements through contact holes formed in said organic resin film; and  
 a driver circuit comprising at least one IC chip for driving said switching elements,  
 wherein said IC clip is formed on a flexible support and said flexible support is connected to said substrate.  
 
     
     
       25. The display device according to  claim 24  wherein said organic resin film comprises polyimide. 
     
     
       26. The display device according to  claim 24  wherein said driver circuit includes a first driver circuit including said IC chip and electrically connected to said plurality of second signal lines and a seconds driver circuit comprising second thin film transistors and electrically connected to said plurality of first signal lines. 
     
     
       27. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one first thin film transistor, wherein a gate electrode of said first thin film transistor is electrically connected to one of said plurality of fitst signal lines and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 an organic resin film formed over said switching elements;  
 a plurality of pixel electrodes formed over said organic resin film and electrically connected to said switching elements through contact holes formed in said organic resin film; and  
 a first driver circuit cornpnsing at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines wherein said second driver circuit comprises second thin film transistors formed over said substrate,  
 wherein said IC chip is mounted over said substrate.  
 
     
     
       28. The display device according to  claim 27  wherein said organic resin film comprises polyimide. 
     
     
       29. The display device according to cIaim  27  wherein each of said first and second thin film transistors has a top-gate structure. 
     
     
       30. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one first thin film transistor wherein a gate electrode of said first thin film transistor is electrically connected to one of said plurality of first signal lines and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 a smoothing film formed over said switching elements;  
 a plurality of pixel electrodes formed over said smoothing film and electrically connected to said switching elements through contact holes formed in said smoothing film; and  
 a first driver circuit comprising at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines, wherein said second driver circuit comprises second thin film transistors formed over said substrate.  
 
     
     
       31. The display device according to  claim 30  wherein each of said first and second thin film transistors has a top-gate structure. 
     
     
       32. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one thin film transistor;  
 a smoothing film formed over said switching elements;  
 a plurality of pixel electrodes formed over said smoothing film and electrically connected to said switching element through contact holes formed in said smoothing film; and  
 a driver circuit comprising at least one IC chip for driving said switching elements,  
 wherein said IC chip is formed on a flexible support and said flexible support is connected to said substrate.  
 
     
     
       33. The display device according to  claim 32  wherein said driver circuit includes a first driver circuit including said IC chip and electrically connected to said plurality of second signal lines and a second driver circuit comprising second thin film transistors and electrically connected to said plurality of first signal lines. 
     
     
       34. A display device comprising:
 a substrate;  
 a plurality of first signal lines formed over said substrate;  
 a plurality of second signal lines extending across said first signal lines over said substrate;  
 a plurality of switching elements formed at each intersection of said first and second signal lines, each of said switching elements comprising at least one first thin film transistor, wherein a gate electrode or said first thin film transistor is electrically connected to one of said plurality of first signal lines and an impurity region of said first thin film transistor is electrically connected to one of said plurality of second signal lines;  
 a smoothing film formed over said switching elements;  
 a plurality of pixel el&trodes formed over said smoothing film and electrically connected to said switching elements through contact holes formed in said smoothing film; and  
 a first driver circuit comprising at least one IC chip electrically connected to said plurality of second signal lines; and  
 a second driver circuit electrically connected to said plurality of first signal lines wherein said second driver circuit comprises second thin film transistors formed over said substrate,  
 wherein said IC chip is mounted over said substrate.  
 
     
     
       35. The display device according to  claim 11  wherein said driver circuit includes a first driver circuit including said IC chip and electrically connected to said plurality of second signal lines and a second driver circuit comprising second thin film transistors and electrically connected to said plurality of first signal lines. 
     
     
       36. The display device according to  claim 1  wherein each of said first and second driver circuits comprises a shift register circuit. 
     
     
       37. The display device according to  claim 6  wherein each of said first and second driver circuits comprises a shift register circuit. 
     
     
       38. The display device according to  claim 17  wherein each of said first and second driver circuits comprises a shift register circuit. 
     
     
       39. The display device according to  claim 21  wherein each of the first and second driver circuits comprises a shift register circuit. 
     
     
       40. The display device according to  claim 27  wherein each of the first and second driver circuits comprises a shift register circuit. 
     
     
       41. The display according to  claim 30  wherein each of the first and second driver circuits comprises a shift register circuit. 
     
     
       42. The display device according to  claim 34  wherein each of the first and second driver circuits comprises a shift register circuit. 
     
     
       43. The display device according to  claim 1  wherein each of said first and second comprises a latch circuit. 
     
     
       44. The display device according to  claim 6  wherein said first driver circuit comprises a latch circuit. 
     
     
       45. The display device according to  claim 17  wherein said first driver circuit comprises a latch circuit. 
     
     
       46. The display device according to  claim 21  wherein said first driver circuit comprises a latch circuit. 
     
     
       47. The display device according to  claim 27  wherein said first driver circuit comprises a latch circuit. 
     
     
       48. The display device according to  claim 30  wherein said first driver circuit comprises a latch circuit. 
     
     
       49. The display device according to  claim 34  wherein said first driver circuit comprises a latch circuit.